Question

Are there any difference between these 2 codes ? Which one should be used ?

asp.net 4.0 , c#

code 1 :

using System;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data;

public static class DbConnection
{
    public static string srConnectionString = "server=localhost;database=mydb;uid=sa;pwd=mypw;";

    public static DataSet db_Select_Query(string strQuery)
    {
        DataSet dSet = new DataSet();

        try
        {
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                SqlDataAdapter DA = new SqlDataAdapter(strQuery, connection);
                DA.Fill(dSet);
            }
            return dSet;
        }
        catch
        {
            if (srConnectionString.IndexOf("select Id from tblAspErrors") != -1)
            {
                using (SqlConnection connection = new SqlConnection(srConnectionString))
                {
                    connection.Open();
                    strQuery = strQuery.Replace("'", "''");
                    SqlCommand command = new SqlCommand("insert into tblSqlErrors values ('" + strQuery + "')", connection);
                    command.ExecuteNonQuery();
                }
            }
            return dSet;
        }
    }

    public static void db_Update_Delete_Query(string strQuery)
    {
        try
        {
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                SqlCommand command = new SqlCommand(strQuery, connection);
                command.ExecuteNonQuery();
            }
        }
        catch
        {
            strQuery = strQuery.Replace("'", "''");
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                SqlCommand command = new SqlCommand("insert into tblSqlErrors values ('" + strQuery + "')", connection);
                command.ExecuteNonQuery();
            }
        }
    }
}

code 2 :

using System;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data;

public static class DbConnection
{
    public static string srConnectionString = "server=localhost;database=mydb;uid=sa;pwd=mypw;";

    public static DataSet db_Select_Query(string strQuery)
    {
        DataSet dSet = new DataSet();

        try
        {
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                using (SqlDataAdapter DA = new SqlDataAdapter(strQuery, connection))
                {
                    DA.Fill(dSet);
                }
            }
            return dSet;
        }

        catch
        {
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                if (srConnectionString.IndexOf("select Id from tblAspErrors") != -1)
                {
                    connection.Open();
                    strQuery = strQuery.Replace("'", "''");

                    using (SqlCommand command = new SqlCommand("insert into tblSqlErrors values ('" + strQuery + "')", connection))
                    {
                        command.ExecuteNonQuery();
                    }
                }
            }
            return dSet;
        }
    }

    public static void db_Update_Delete_Query(string strQuery)
    {
        try
        {
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                using (SqlCommand command = new SqlCommand(strQuery, connection))
                {
                    command.ExecuteNonQuery();
                }
            }
        }
        catch
        {
            strQuery = strQuery.Replace("'", "''");
            using (SqlConnection connection = new SqlConnection(srConnectionString))
            {
                connection.Open();
                using (SqlCommand command = new SqlCommand("insert into tblSqlErrors values ('" + strQuery + "')", connection))
                {
                    command.ExecuteNonQuery();
                }
            }
        }
    }
}

Answer 1

If you have ReSharper to do it for you or are willing to download them manually, you could look at the source code for SqlCommand and SqlDataAdapter and see if their Dispose() method actually does anything. If not, it’s probably safe to leave out the using statements around them.